From Hobart to the southern tip of Maria Island, you can save around 24nm by going through the Canal (46nm) as opposed to Via Tasman (70nm).

The attached chartlet of Marion Narrows provides depth information laid over Chart AUS169.

  • The chartlet is NOT FOR NAVIGATION PURPOSES and has been provided for guidance purposes only
  • Mariners are strongly recommended to use AUS169 when navigating this area
  • The depths on the chartlet are those measured on the date shown on the chartlet
  • Depths are in metres, referenced to Chart Datum using the Hobart Tide Tables
  • Conditions continually change at the Narrows and depths experienced may differ from the chartlet.

The attached route data provides a vessel track through the Marion Narrows area as of the dates shown on the file. These tracks can be downloaded to mobile devices and to some chart plotters via portable storage devices such as an SD card. Conditions continually change at the Narrows and the deepest route may differ from those provided.


  • Mariners are advised not to attempt to enter Blackman Bay through the Narrows in heavy north-easterly conditions .(especially with an out-going tide);
  • Only vessels with a shallow draft should transit the Narrows and Denison Canal and only after the skipper has sought local knowledge;
  • Navigate only at high tide and in daylight hours.

Tidal Streams

  • The main stream of the flood tide runs into Blackman Bay – ie, in a north-easterly direction at the Denison Canal and a south-westerly direction at the Marion Bay Narrows. The reverse applies for an ebb tide.
  • Tide times can be calculated with reference to tide tables with the following adjustments:
    • Flood Stream commences 2 hours 27 minutes after low water at Hobart
    • Ebb Stream commences 2 hours 16 minutes after high water at Hobart

Remember to adjust for daylight saving time. Mariners should remember that tide conditions may differ depending on factors such as barometric pressure, prevailing winds etc.

Live Safety Camera covering entrance to the Marion Narrows

Tas Maritime Radio (TMR) has installed a live camera at the Marion Narrows to monitor the transit of vessels and provide vision of current sea conditions.